/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
/* Copyright (c) 2021~2022 Hengqi Chen */
#include <vmlinux.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_core_read.h>
#include "core_fixes.h"
#include "mdflush.h"

struct {
    __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
    __type(key, __u32);
    __type(value, __u32);
} events SEC(".maps");

SEC("fentry/md_flush_request")
int BPF_PROG(md_flush_request, void* mddev, void* bio) {
    __u64 pid = bpf_get_current_pid_tgid() >> 32;
    struct event event = {};
    struct gendisk* gendisk;

    event.pid = pid;
    gendisk = get_gendisk(bio);
    BPF_CORE_READ_STR_INTO(event.disk, gendisk, disk_name);
    bpf_get_current_comm(event.comm, sizeof(event.comm));
    bpf_perf_event_output(ctx, &events, BPF_F_CURRENT_CPU, &event,
                          sizeof(event));
    return 0;
}

char LICENSE[] SEC("license") = "Dual BSD/GPL";
